Sunbird Diversity East Africa 2027: the Hummingbirds of the Old World and the Nectar Guild
The sunbirds are the East African ornithological circuit’s “hummingbird equivalent” — the 30 to 45 sunbird species present in the Tanzania and Kenya safari ecosystems being the most diverse nectar-feeding bird family in the Afrotropical region. The East African safari visitor on the standard Tanzania-Kenya savannah circuit encounters 8 to 15 sunbird species on a 7 to 10 day trip . The sunbird’s convergent evolution with the hummingbird: the sunbirds are the Old World’s convergent equivalent of the New World hummingbirds but achieved through entirely different anatomy and different evolutionary origin . The 5 most distinctive East African sunbird species for the 2027 safari visitor: the superb sunbird ; the variable sunbird ; the Marico sunbird ; the malachite sunbird with the brilliant iridescent emerald-green plumage and the 10 to 14 centimeter tail-streamers, found in the highland zones above 1,800 meters in the Aberdare National Park, Mount Kenya and Ngorongoro rim’s alpine zone]; and the scarlet-chested sunbird .
Sunbird Feeding Ecology: Bill Morphology, Nectar Theft and the Plant Mutualism
The sunbird’s primary food is floral nectar supplemented by arthropods . The bill morphology: the sunbird’s curved bill is the primary adaptation for the nectar-feeding from the tubular or cup-shaped flowers of the Leonotis nepetifolia , the Aloe species , the Erythrina species , and the Acacia tortilis flower . The nectar theft: the sunbird’s bill morphology — though generally well-matched to the primary flower’s corolla length — produces the “nectar theft” behavior when the sunbird encounters a flower whose corolla is too long for the bill to reach the nectary from the flower’s entrance: the sunbird punctures the base of the corolla with the bill accessing the nectary from the outside . The sunbird’s territorial behavior: the sunbird maintains a “nectar territory” and the smaller honeyeaters by the “chase display” — the rapid aerial chase at 40 to 55 km/h that the territorial sunbird initiates within 3 to 8 seconds of the intruder’s appearance at the defended flower]. The malachite sunbird’s highland territory: the malachite sunbird’s territory in the Aberdare National Park and Mount Kenya’s giant heather zone centers on the giant lobelia and the giant groundsel flowering spikes, the territorial male defending the single most productive lobelia spike against rival males for the 3 to 5 week flowering duration of the individual spike.
Sunbird Breeding: Nest Architecture, the Hanging Bag and the Male Display
The sunbird’s nest is the most architecturally elaborate nest of any East African bird family — the female’s pendant nest too thin for any climbing predator to cross] is constructed from the spider web , grass, plant fibers and the “porch” . The nest building: the female builds the nest solo , the construction period at 7 to 15 days , and the completed nest at 8 to 15 centimeters in length with the entrance hole at the lower third’s lateral position . The male’s display: the male sunbird’s iridescent plumage display producing the iridescent flash visible at 20 to 80 meters only at the correct observation angle — the male’s breast-puffing display is the primary sexual selection signal, the female selecting the male with the most intense and most consistent iridescent display as the breeding partner. The sunbird’s contribution to East African plant ecology: the sunbird guild’s combined pollination services to the Acacia, Aloe, Leonotis, Erythrina and Lobelia species in Tanzania and Kenya are estimated at 60 to 80 percent of the total pollination of these 5 plant genera in the sub-Saharan African range — the sunbird’s loss from any ecosystem would produce the reproductive failure of 40 to 60 percent of the nectar-dependent plant species in that ecosystem, with cascading effects on the frugivore community and the seed dispersal network.
Best Sunbird Viewing 2027: the Garden, the Forest Edge and the Highland Zone
The 2027 sunbird viewing guide for Tanzania and Kenya: the sunbird is the most easily viewed and most actively photographable of all the East African small birds — the perching behavior , the bright iridescent plumage , and the predictable flower-visiting behavior make the sunbird the most “stationary and predictable” small-bird photography target in the East African circuit. Tanzania’s best sunbird sites 2027: the Ngorongoro Crater rim’s forest zone and the tacazze sunbird to the hotel garden’s veranda-viewing flower beds, the easiest sunbird photography in Tanzania]; the Arusha National Park’s Momella Lakes area ; and the Kilimanjaro forest zone . Kenya’s best sunbird sites 2027: the Lake Nakuru National Park ; the Samburu-Buffalo Springs Reserve ; and the Aberdare National Park , accessible from the Ark and the Aberdare Country Club’s moorland drive].